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A168677
Lexicographically earliest positive integer sequence such that no sum of consecutive terms is a positive power of 4.
2
1, 1, 1, 5, 1, 1, 1, 9, 1, 1, 1, 5, 1, 1, 1, 9, 1, 1, 1, 5, 1, 1, 1, 9, 1, 1, 1, 5, 1, 1, 1, 9, 1, 1, 1, 5, 1, 1, 1, 9, 1, 1, 1, 5, 1, 1, 1, 9, 1, 1, 1, 5, 1, 1, 1, 9, 1, 1, 1, 5, 1, 1, 1, 9, 1, 1, 1, 5, 1, 1, 1, 9, 1, 1, 1, 5, 1, 1, 1, 9, 1, 1, 1, 5, 1, 1, 1, 9, 1, 1, 1, 5, 1, 1, 1, 9, 1, 1, 1, 5, 1, 1, 1, 9, 1
OFFSET
1,4
COMMENTS
It appears that the sequence is periodic with period (1,1,1,5,1,1,1,9) of length 8.
EXAMPLE
Assume that a(1) - a(7) have been determined as {1,1,1,5,1,1,1}. Then a(8)=1 gives consecutive terms 1,1,1,1, summing to 4; a(8)=2 gives 1+1+2=4; ... etc...; a(8)=8 gives 5+1+1+1+8=16; but a(8)=9 is ok, giving no sum of consecutive terms equalling 4,16,64,... .
MATHEMATICA
LinearRecurrence[{0, 0, 0, 0, 0, 0, 0, 1}, {1, 1, 1, 5, 1, 1, 1, 9}, 105] (* Ray Chandler, Aug 25 2015 *)
CROSSREFS
Sequence in context: A369364 A322837 A348978 * A345939 A140210 A360720
KEYWORD
nonn
AUTHOR
John W. Layman, Dec 02 2009
STATUS
approved